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<head>
  <meta charset="UTF-8">
  <meta name="viewport" content="width=device-width, initial-scale=1.0">
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  <title>Document</title>
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<body>
  
</body>
<script>
  var num=name=url=19;
  console.log(num);
  console.log(name);
  console.log(url);

  //name在bom中有特殊定义，代表窗口号
  console.log(this);
  console.log(window.location.host);
  

  var web=11;
  console.log(typeof web);

  web="哈哈";
  console.log(typeof web);
  web={aa:""};
  console.log(typeof web);
  
  
</script>
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